Short-distance hauling solution

Everybody does it: try to carry as much as possible without dropping, spilling or breaking anything.

It’s human nature to load up with as much as possible to reduce the number of trips and save time. When carrying groceries into the house, for example, no one makes three trips if they can find a way to carry extra bags and complete the job in two.

For hauling aggregate, increasing load capacity is about more than saving time; it’s about increasing revenue. However, in the case of Caldwell Stone Co. in Danville, Kentucky, the risk of spilling debris on a paved highway results in loads reaching a point of diminishing return before achieving each truck’s rated capacity.

“I can see a truck crossing the road now,” says Clay Albright, vice president at Caldwell, while looking out over the quarry from the main office. “Our trucks don’t haul more than a half mile from the stockpile to neighboring asphalt and cement plants, but we have to be extra careful to not over fill.”

Albright is referring to the danger – and cleanup expense – of spilling aggregate onto a public blacktop. While Caldwell’s articulated trucks are rated at 35 tons, they are forced to either under haul to prevent spillage or find a way to carry more with each trip.

A century at Caldwell

Caldwell Stone began in the 1920s, and nearly 50 years ago, Albright’s grandfather purchased the quarry from the founder, W.P. Caldwell.

“I’m third generation,” Albright says. “I started mowing the grass here as a teen and have been full time since finishing college in 2006, not long after my granddad passed away.”

Albright’s father and grandfather kept the quarry’s focus solely on extracting and crushing stone. As a result, a block plant, ready-mix plant and asphalt plant – which all rely on Caldwell Stone for raw material – established themselves adjacent to the quarry.

Thanks to their close proximity, Albright’s trucks deliver crushed aggregate directly to the neighboring plants and – despite traveling a short distance on a county blacktop – are able to do so using their articulated dump trucks.
“As soon as our trucks exit the property, they cross the blacktop and head uphill to the asphalt and cement plants,” Albright says.

While spilled material equates to lost revenue for any operation, Caldwell Stone is especially careful to avoid spilling on the public roadway.

“Going up the hill, rocks shift in the back and, if the truck’s at capacity, materials inevitably spill out,” Albright says. “To prevent that, we need to fill trucks to less than their rated capacity or equip each with a tailgate.”

Without tailgates, Albright estimates Caldwell’s 35-ton A35C Volvo hauls, on average, 25 to 30 tons, depending on the materials – a problem the quarry has dealt with for decades.

To combat this, Caldwell added tailgates to some trucks, but the company experienced mixed results.

Tailgate trial and error

Before Albright joined the quarry full time, his father and grandfather bought tailgates for the Volvo dump trucks, which deliver to the nearby plants. While Albright doesn’t recall the brand or year the tailgates were purchased, he hasn’t forgotten the hassle of keeping up with repairs.

Leaving the quarry, large rocks would tumble down the bed and hit the tailgate, breaking frame welds and cables. Then, according to Albright, during a period of heavy stripping, the tailgates were damaged so frequently and severely that they were bending and breaking off the frame.

“Initially we kept up with repairs,” Albright says. “We’d remove the tailgate – which takes about an hour – repair the welds and straighten out the dents and other damage. Eventually, though, they became so bent out of shape that we gave up.”

During the past dozen years, Albright estimates the tailgates were a problem for six to eight of those years. For the last few years, the tailgates sat abandoned and defeated, leaning against the side of a building.

“In the end, they were more work to maintain than they were worth,” Albright says. “If we didn’t know better, we may have kept repairing them, but we know from experience how a good tailgate should hold up.”

After all, they have a benchmark for comparison.

Contrasting tailgates

Before deciding to experiment with low-cost tailgates on its articulated trucks, Caldwell Stone purchased a heavy-duty Philippi-Hagenbuch (PHIL) Autogate tailgate for one of its main pit trucks – a Cat 769D rock truck – to prevent spillage while traversing the quarry’s often-uneven terrain.

In stark contrast to its articulated trucks’ tailgates, the PHIL Autogate tailgate is still going strong more than 20 years later.

“There’s no comparison,” Albright says. “I think I’ve ordered parts for our PHIL tailgate once in my 12 years – and not even due to normal wear. It was damaged when a driver tried to pass a dozer on a narrow section of the haul road and the outrigger caught the blade.”

The tailgate’s longevity is no accident. Philippi-Hagenbuch not only engineers unique tailgates for every make and model of off-highway truck and body combination, but it takes into consideration the height of the truck’s sideboards, the material being hauled and haul road conditions. According to Philippi-Hagenbuch, it also utilizes high-strength steel throughout the entire tailgate for superior durability without adding weight or bulk.

Also, the Illinois-based manufacturer relies on its hinge and leverage system, which opens at a steady rate as the truck body lifts, providing the largest possible opening clearance at full dump. This eliminates the need for additional hydraulics, reducing the number of wear parts to further ensure exceptional service life as well as minimal maintenance and repairs.

It was only after seeing firsthand how PHIL tailgates hold up that Albright became acquainted with one of the people behind the brand. He and Josh Swank, vice president of sales and marketing at Philippi-Hagenbuch, met about 10 years ago at a National Stone, Sand and Gravel Association Young Leaders event.

“He’s a great guy,” Albright says of Swank. “We met there my first year when I was in my early 20s. Josh and his wife, Danette, showed me around and made me feel welcome. Ever since then, we’ve stayed in touch.”

Due to the longevity of his PHIL tailgate, Albright has never had an opportunity to do business with Swank. Now, after abandoning any hope of salvaging the old non-PHIL tailgates, Albright suspects it’s time for that to change.

“Since scrapping those tailgates, we’ve been underhauling when delivering to the processing plants,” he says. “Because we can’t risk spilling rocks on the pavement, we’re forced to keep loads under 30 tons.”

The repercussions for under hauling by five or more tons can add up quickly.

Underhauling

On the days Caldwell Stone direct dumps aggregate to the concrete plant, it delivers as much as 500 tons of material in an eight-hour day.

Delivering 500 tons, 30 tons at a time, requires 16 to 18 trips. With a tailgate, Caldwell can fill 35-ton trucks to capacity and deliver the same amount in three to five fewer loads, which means reduced fuel consumption, less wear on the trucks and tires, and fewer opportunities for something to go wrong while crossing a public highway.

While Caldwell Stone is able to meet demand using its current delivery system, Albright speculates the potential revenue boost with tailgates would be exponential for a quarry with high-capacity on-site processing plants. For example, continuing the aforementioned scenario over the course of an entire shift, a single truck could deliver significantly more tons in an eight-hour workday.

Assuming an average aggregate cost of $10 per ton, one truck could deliver about $1,750 more material each day, $8,750 more per week and as much as $430,000 more per year.

For Albright, reducing the number of daily cycles and trips onto a public road are reason enough to rely on PHIL tailgates on the quarry’s trucks.

“We plan to buy a PHIL tailgate for our A40D in the next month or two,” Albright says. “The peace of mind, along with the reduced truck wear and labor costs we can expect, will make it worthwhile. And with the years of reliability we’ve seen with our other PHIL tailgate, this one should pay for itself quickly and add up to greater profits for us over its lifespan.

“We’re expecting ROI in fewer than two weeks,” he adds.

Albright is confident that, like Caldwell’s other PHIL tailgate, the new one won’t need many repairs. And because of the longevity of PHIL products, he expects it will be decades before he can tally up his total return on investment for the purchase. After all, the 20-some-year-old tailgate is still going strong.

It shouldn’t take long, however, for Albright to confirm he’s found a long-term solution for carrying more with each trip.

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Brittany Luthi is a writer for the aggregates and mining industries.